2 Matching Annotations
  1. Jul 2018
    1. On 2016 Feb 16, Bernard Baars commented:

      This article is one of the most important neuroscience contributions in recent history.

      Mircea Steriade published brain recording studies, in both single-cell and population oscillations in cortex. (The cortico-thalamic system).

      Because animal researchers were able to perform direct intracranial recordings long before similar human studies appeared, they published many discoveries that other neuroscientists and psychologists are now seeing in their own data.

      Steriade's central finding is that "The cerebral cortex and thalamus constitute a unified oscillatory machine displaying different spontaneous rhythms that are dependent on the behavioral state of vigilance."

      This was at a time of extreme skepticism about human scalp EEG, which suffers a thousand-fold loss of voltage due to the attenuating effects of the cranium, scalp muscles, and other protective tissue layers. Direct brain recordings are measured in millivolts, while scalp recordings show up in microvolts, with corresponding vulnerability to electrical noise from the eyes, scalp muscles, and stray EM fields.

      Animal researchers solved those problems by learning how to insert electrodes directly into the brain, in species where it was ethically allowable to do so.

      Today we are now seeing similar results in humans, using surgical implants prior to epileptic surgery. (See about 200 articles in PubMed under "iEEG" or "ECog". Surprisingly, iEEG has the highest temporal and spatial resolution of any brain imaging technique today.)


      This comment, imported by Hypothesis from PubMed Commons, is licensed under CC BY.

  2. Feb 2018
    1. On 2016 Feb 16, Bernard Baars commented:

      This article is one of the most important neuroscience contributions in recent history.

      Mircea Steriade published brain recording studies, in both single-cell and population oscillations in cortex. (The cortico-thalamic system).

      Because animal researchers were able to perform direct intracranial recordings long before similar human studies appeared, they published many discoveries that other neuroscientists and psychologists are now seeing in their own data.

      Steriade's central finding is that "The cerebral cortex and thalamus constitute a unified oscillatory machine displaying different spontaneous rhythms that are dependent on the behavioral state of vigilance."

      This was at a time of extreme skepticism about human scalp EEG, which suffers a thousand-fold loss of voltage due to the attenuating effects of the cranium, scalp muscles, and other protective tissue layers. Direct brain recordings are measured in millivolts, while scalp recordings show up in microvolts, with corresponding vulnerability to electrical noise from the eyes, scalp muscles, and stray EM fields.

      Animal researchers solved those problems by learning how to insert electrodes directly into the brain, in species where it was ethically allowable to do so.

      Today we are now seeing similar results in humans, using surgical implants prior to epileptic surgery. (See about 200 articles in PubMed under "iEEG" or "ECog". Surprisingly, iEEG has the highest temporal and spatial resolution of any brain imaging technique today.)


      This comment, imported by Hypothesis from PubMed Commons, is licensed under CC BY.